A fish agri-food system is an interconnected and interdependent system involving components of fish production through to processing, marketing and consumption. The CGIAR Research Program on Fish Agri-Food Systems (FISH) is a collaborative global partnership that aims to enhance the sustainability, productivity and resilience of fish agri-food systems, contributing to global goals for poverty reductions, food and nutrition security, and improved resilience of natural resource systems. The overarching research question guiding the program is: How can we optimize the contributions of aquaculture and small-scale fisheries to reduce poverty and improve food and nutrition security, while enhancing environmental sustainability?